Rocket propulsion method



y 2 1 A. ZLETZ ET AL 2,896,404

ROCKET PROPULSION METHOD Filed Feb. 16. 1953 OX/D/ZER Alex Z/efz Don R. Carmody ATTORNEY IN V EN TORS I v 2,896,404 ROCKET PROPULSION rmrnon Alex Zletz; Park. Forest, and Don R. Carmody, Crete, ]Ill., assignors to Standard Oil Company, Chicago,.Ill.,

a'corporation of Indiana Application February 16, 1953, Serial No. 336,907

12' Claims. (Cl. 60-354) This. invention relates to the generation of gas. More particularly, it relates to reaction propulsion by the hypergolic reaction of a liquid fuel and a liquid oxidizer. Still more particularly, the invention relates to a method of rocket propulsion by the hypergolic reaction of a fuel and a hydrogen peroxide oxidizer, which materials spontaneously react to generate gas at high pressure and high temperature.

Reaction propulsion is now being used for many aerial purposes. For many uses it is necessary to operate with a fuel system which is not dependent on atmospheric oxygen. This fuel system may consist of a single selfcontained propellant or it may consist of a separate fuel anda separate oxidizer, i.e., a bipropellant system.

Inv the bipropellant system the fuel and the oxidizer are introduced separately and simultaneously into the combustion chamber of the reaction motor. The products: of oxidation from the reaction of the fuel and the oxidizer are discharged through an orifice at the exit end of thecombustion chamber and thereby produce thedriving force. Because of the possibilities of electrical: and/r mechanical failure of the auxiliary methods of-ignition' such as a spark or a hot surface, it is preferred to use a self-igniting fuel system. A fuel which is selfigniting; i.e., spontaneously combustible when contacted with. an oxidizer, is known as a hypergolic fuel.

Temperature has an important effect on the hyperg'oli'c activity-- of fuels. The temperature at the earths surface may vary from ahigh of about +125 F. to a low of. asmuch as -65'F.; in general temperatures below about 20 or -30 F. are exceptional. Thus surface-toair. missiles or rocket-driven aircraft should be capable of operation when the temperature of the fuel andv the oxidizerat the moment of initial contact in the combustionchamber of the rocket motor is on the order of 20 F. Temperatures at high altitudes are frequently on the order of 65 F. and are known to approach 1 00 F. Thus an air-to-air missile should be able to operate satisfactorily when the temperature of the fuel and. the oxidizer at' the moment of initial contacting in the combustion chamber is on the order of 65 F.

The more common oxidizers are white fuming nitric acid red fuming nitric acid and nitric acid-sulfuric acid mixtures; While these nitric acid oxidizers operate'satisfactorily over a wide range of atmospheric temperatures they have importantdrawbacks. The nitric acid oxidizers are extremely corrosive; they have poor storage stability; they give off. toxic gases; and special precautions must beitakenby personnel who handle these oxidizers.

Concentrated aqueous hydrogen peroxide solutions have excellent: storage stability and do not give olf harmful gas; However, these aqueous hydrogen peroxide solutions. such as, 90% hydrogen peroxide have the disadvantage of comparatively high freezing points, e.g., 90% hydrogenperoxide solution freezes at +l2 F. The freezing point of 80% hydrogen peroxide is 9 F., but the activity of this solution toward the prior art fuels is markedly lower than the 90% H 0 solution. The freezingpoint. of aqueous hydrogen peroxide solutions can be' depressed by dissolving therein inorganic salts,

preferably; ammonium nitrate. Thus asolution contain-- ing weight percent of ammonium nitrate and in: which the hydrogen peroxide-water portion contains 90 weight percent of H 0 has a freezing'point of about -30 F. A so-called 80% H O 30% NH NO solution has a freezing point of below 70 F.-

Concentrated aqueous hydrogen peroxide solutions have been used as monopropellants by catalytically decomposingfthe hydrogen peroxide using. such catalysts as potassium permanganate or copper oxide. since" the decomposition products contain free-oxygen the monopropellant system is ineflicient. However,v fuels which are hypergolic with nitric acid oxidizers maybe much less active or even inactive with concentratedfH o solutions; Anhydrous hydrazine is usually considered to be the only fuel that is suthciently hypergolic with concentrated H 0 solutions to be practical; however, hydrazine has the disability of a comparatively high freezing point Some fuels are operative with H 0 solutions in the presence of a H 0 decomposition catalyst.

An object of this invention is a method of generating gas by the hypergolic reaction of a fuel and a hydrogen peroxide oxidizer. Another object is a method of reaction propulsion by the hypergolic interaction of a fuel and a hydrogen peroxide oxidizer. Still another object is a method of reaction propulsion by the hypergolic interaction of a hydrogen peroxide oxidizer and afuel which contains appreciable amounts of hydrocarbons, particularly non-hypergol-ic liquid hydrocarbons. Another particular object is a method. of rocket propulsion by the hypergolic interaction of a defined organic. thioborate and a defined hydrogen peroxide oxidizer when the temperature of the fueland the oxidizer is. above about -20" F. Other objects will become apparent in the course of the detailed description of the invention.

A method has been discovered forgenerating gas,

' which gas may be used as a substitute for compressed air for certain purposes or for driving the turbine of a jet engine or for rocket propulsion,,which method comprises contacting.

(1) A hypergolic fuel consisting essentially of a. thi'o borate-having the empirical formula, RR'R."S B wherein: B represents the element boron, S represents the element sulfur, and R, R and R represents hy drocarbon radicals selected from the group consisting of aliphatic radicals containing from 1 to'3 carbon" atoms and cycloaliphatic radicals containing 3 car bon atoms and wherein the total: number of carbon: atoms in the thioborate molecule is between 3 and 7, and. Y

(,2). An oxidizer selected from the group consisting-of (a) Aqueous hydrogen peroxide solutions which contain at least about 80. weight percent of H 0 and the remainder is essentially water and (b)- Aqueous hydrogen peroxide-inorganic salt solutions wherein the hydrogen peroxide-water portion contains at least about weight percent of H202- Y A mixed fuel made up of trimethyl thioborate which contains as much as 60 volume percent of miscible hydrocarbon is hypergolic with aqueoushydrogen peroxidesolutions containing at least about weight percentof hydrogen peroxide when the fuel and the oxidizer are. at.

tivity with the same oxidizer. However, by proper selec-- tion of the thioborate, it is possible to obtain a hypergolic reaction with .a tolerable ignition delay whenthe thioborate' and the'oxidizer are at a' temperature of about 20 F. at the moment of initial contact in the gas generating chamber.

These organic thioborates have the generic empirical formula. RRR"S B. It is believed that the structural formula. is;

(Herein these compounds will be referred to as thioborates although it is to be understood that the name trithioborates is also assigned to these compounds by some writers.)

The thioborates which are suitable for the purposes of this invention contain hydrocarbon radicals R, R and R containing from 1 to 3 carbon atoms. These hydrocarbon radicals may be paraflinic, i.e., methyl, ethyl, isopropyl and n-propyl; or they may be olefinic, i.e., ethenyl, propenyl, isopropenyl, ethinyl and propinyl. Also, the hydrocarbon radicals may be cycloaliphatic e.g., cyclopropyl and cyclopropenyl. The terms aliphatic radica and cycloaliphatic radical are intended to include saturated and unsaturated radicals. Although any single hydrocarbon radical may contain as many as 3 carbon atoms, the total number of carbon atoms present in a thioborate which is suitable for the purposes of this invention must be between 3 and 7. The presence of more than 7 carbon atoms in the molecule results in in such a long ignition delay on the reaction between the thioborate and the hydrogen peroxide oxidizer as to render that particular propellant system unsuitable for rocket propulsion.

The most suitable thioborates for the purposes of this invention are the trialkyl thioborates wherein the alkyl radicals are selected from the group consisting of methyl, ethyl and mixtures thereof. For operation where the thioborate and the oxidizer will be at a temperature of about -20 F. at the moment of initial contacting of the thioborate and the oxidizer, the preferred thioborate is trimethyl thioborate.

A mixed fuel which is suitable for the generation of gas for rocket propulsion when the fuel and the oxidizer, which should be at least about 90% H at the moment of initial contact, are at a temperature of at least about +60 F. can be made by mixing trimethyl thioborate with a miscible hydrocarbon. Although the minimum amount of thioborate necessarily present in said mixed fuel will vary with the type of hydrocarbon, usually at least about 40 volume percent of thioborate must be present. In general, petroleum hydrocarbon fractions are suitable materials as for example those fractions boiling between about 300 and 600 P. which correspond to the fuel requirement of military jet engines. Aromatic hydrocarbons which boil below about 600 F. are suitable hydrocarbons for this purpose. The hypergolic activity of the mixed fuel can be improved at temperatures below about +60 F. by using as the hydrocarbon component olefinic hydrocarbons such as thermally cracked naphthas and gas oils or turpentine. Conversely, at temperatures above about 60 F., a hypergolic mixed fuel containing less than about 40 volume percent of thioborate is obtainable by the use of these olefinic hydrocarbons.

The oxidizers of this invention are either concentrated aqueoushydrogen peroxide solutions or aqueous hydrogen peroxide solutions containing dissolved inorganic salts, for example, ammonium halides, sodium sulfate, sodium nitrate, etc.; the inorganic nitrates are preferred. The concentrated aqueous hydrogen peroxide solutions should contain at least about 80 weight percent of H 0 the remainder of the solution is essentially water. Concentrated aqueous hydrogen peroxide solution as made commercially is virtually only H 0 and water. In order to improve storage stability small amounts of stabilizers are commonly added to the solution, e.g., sodium stannate, tetrasodium pyrophosphate, adipic acid, tartaric acid; in general only trace amounts of stabilizers are added so that the solution consists essentially of hydrogen peroxide and water. The hypergolic activity of the aqueous hydrogen peroxide solution is improved by increasing the concentration of the peroxide. Commercially available 90% H 0 solution is a preferred oxidizer. Still more concentrated solutions are better when operation above the freezing point of the solution is desired.

In order to depress the freezing point of aqueous hydrogen peroxide solutions soluble inorganic salts are dis solved therein, e.g., sodium nitrate, potassium nitrate and ammonium nitrate have been used. The preferred salt is ammonium nitrate. These salt-containing solutions are commonly designated in terms of the weight percent of salt in the total solution and the weight percent of hy drogen peroxide present in the aqueous portion of the solution, e.g., 90% H O 40% NH NO indicates that the total aqueous hydrogen peroxide-nitrate solution consists of 40 weight percent of ammonium nitrate and 60 weight percent of aqueous hydrogen peroxide composed of 90 weight percent of H 0 and the remainder essentially water. This particular solution has a freezing point of -30 F. A temperature of 70 F. is attainable with an I-I O --30% NH NO solution. It is preferred to operate in the absence of soluble inorganic nitrate salts because these salts have an adverse effect on the hypergolic activity of the fuels of this invention.

The alkyl thioborates are in general clear, mobile, high-boiling liquids; they are fairly stable when exposed to elevated temperatures in the absence of air, but are extremely susceptible to hydrolysis by atmospheric moisture. Thus they are quite stable when stored in sealed containers such as stoppered flasks and stainless steel drums.

In general the alkyl thioborates have low freezing points, with a great tendency to supercool, i.e., remain liquid at temperatures below the true freezing points. Also, the minor amounts of impurities present in thioborates as prepared have a beneficial freezing point depressing quality. An amount of impurity suflicient to noticeably depress the freezing point of the pure thioborate does not have an appreciably adverse effect on hypergolic activity of the impure material.

It has been observed that the presence of minor amounts of hydrolysis products (and oxidation products) of the thioborates have no appreciable effect on hyper golic activity. It is intended to include within the scope of the invention the use of aliphatic trithioborates which contain minor amounts of impurities resulting from the preparation thereof, and those which contain minor amounts of products resulting from atmospheric exposure of the aliphatic trithioborates.

Trimethyl thioborate was prepared as follows: Boron trichloride was introduced into a 3-necked flask which contained methyl mercaptan in the approximate ratio of 3 mols of mercaptan per mol of boron trichloride. Alsoin the flask with the mercaptan was sodium methyl mercaptide in mol ratio to the boron trichloride of 3 to l. The mercaptide was used to react with any HCl formed in the reaction. However, the mercaptide was recovered apparently unreacted. After the addition of boron trichloride over a period of 3 hours at reflux temperature the reaction mixture was maintained at reflux. temperature (about 10 C.) for 4 /2 hours. The cooler was removed from the flask and the flask permitted to reach room temperature while stirring. The pressure in the flask was progressively decreased by withdrawing gaseous materials therefrom, ambient temperature being maintained for the fractionation process. Two overhead fractions, both of which were hypergolic with hydrogen peroxide at ambient temperature, and a so- 5. diunr mercaptide residue were obtained. The lowerboiling overheadfraction was refluxed at sub-atmospheric pressure for about 8 hours to carry the reaction as completely as possible to the formation of trimethyl thioborate and the resulting product was subjected to distill Test. A-

Various trialkyl' thioborates were: tested for hypergolic activity at a temperature of about +70" F. using 0.5 ml. of 90% H O as the oxidizer.

lative fractionation to obtain seven fractions. The last, Run Fuel least volatile fraction analyzed as follows: No. Fuel azgiled Ignition delay ActuaLPertiggtfigi Trimethylthioborate 0.04 sho t.-

0.06 Noigmtionmcent throborate, 0 g 1 percent 0 l sec.

22 e. Considerable efierveseence. 62.90 63.20 Testv B 24.19 28.68 V V r 6.15 5. 96. In. this test several runs were made contacting tnmethyl thioborate at various temperatures using 0.5 ml.

The agreement between the ultimate analysis and the theoretical shows this product to be trimethyl thioborate.

The other physical characteristics of the trimethyl' thioborate are freezing point, 3.5-4.0 C.; boiling point, 59 C; at 2 mm. Hg; specific gravity, 1.09 at 28 C.

Triethyl thioborate was prepared as follows: Ethyl mercaptan was cooled to -65 C. in a 3-necked fiask provided with a Dry Ice condenser and a motor-driven stirrer. Gaseous boron trichloride was passed into the flask in, an amount slightly less than the theoretical. The contents. of the flask werev allowed to come to. room temperature and were stripped of ethyl mercaptan. The material in, the reaction flask fumed strongly when exposed to air.

These materials were placed in a bomb and were treated with additional amounts of ethyl mercaptan while being maintained. at a temperature of 115 C. The material was removed from the bomb and was found to give a slight qualitative test for chlorine.

This: material was given a further treatment with sodium ethyl mercaptide in order to obtain a product that did not fume when exposed to the air. This product was distilled to produce a fraction which was hypergolic with 70% nitric acid at room temperature. Ultimate. analysis of this fraction indicates. that triethyl thioborate had been prepared. The physical characteristicsof the triethyl thioborate are freezing point, 46' C.; boiling point, 64.67 C. at 0.5 mm. of Hg; Specific gravity, 1.06 at 24 C- Triethyl thioborate supercools readily and is quite fluid at 79 C. When exposed to air some solid productsv were produced. The resulting. liquid mixture had afreezing point of -48 C.

The ignition characteristics of various fuels were studied using a drop test. This method utilizes a test tube, 1 in. x 4 in., containing about 0.5 ml. of oxidizer. The fuel to be tested was drawn into a hypodermic syringe. It was then ejected forceably against the oxidizer surface by depressing the syringe plunger. By this method amounts of fuel of as little as 0.01 ml. can be added; Low temperature tests were carried out by cooling the test tube and the oxidizer contained therein by means of a bath; a drying tube inserted into the top of the test tube excluded moisture. The fuel was cooled separately to the desired test temperature. By supercooling it was possible to carry out tests at temperatures below the freezing point of the fuel and/or the oxidizer.

The ignition delay, which is the time elapsing between the addition of fuel to the oxidizer and visual ignition thereof, was determined visually as either (a) very short which corresponds to substantially instantaneous ignition, (11) short, which corresponds to substantially less than 1 second, and (c) more than 1 second, which time was determined by a stop watch.

The following tests illustrate the activity of the thioborates of this invention and hydrazine with hydrogen peroxide oxidizers.

of 90% H O solution as the oxidizer.

Run No. H'zOr Fuel- Temp., Ignitionoxidizer, added, F.- delay percent v m1.

90 0. Short. 90' t 0.06 +32 D0. 90 0. 06 -20 1 sec.

Test C For comparative purposes hydrazine was contacted at H 0 solutions as the oxidizer.

Run 1110, Fuel Temp., No. ox1dizer,, added, F. Ignition delay percent ml.

90 0.05 +70 Very short. 0.03 +70. Short. 80 0.10 +14 No ignition (effervescence);

Test D In order to observe, the effectiveness of thioborate with.

oxidizers consisting. of aqueous hydrogen peroxide ammonium nitrate. solutions, several runs were made at various temperatures using 0.5 of various aqueous hydrogen. peroxiderammonium nitrate solutions as the oxidizer.

Fuel, Oxidizer Run Fuel added, 202- Temp., Ignition N 0. m1 NH NO F. delay percent 9040 +70 ;1 sec. -20 +70 Short. 90 20 20 3 sec.

thioborate. These runs were carried out at about +70 F. using 0.5 ml. of 90% H 0 as the oxidizer.

Mixedfuel I Fuel Run No. added, ,Ignition V01. V01. m1. delay percent percent trimethyln-Octane- 0.04 'Short;

5O 50 0.10 7see. 40 60 1 0.12. 35cc.

These runs show the favorable effect. on ignitiondelayof using larger amounts of fuel inthe test.

It is obvious from. the data. presented abovethatthis invention can be used to generate gas at high pressure. This gascan be used for operating machinery such as compressed air hammers or for aircraft catapults; another important use for this high pressure gas is in the starting of the turbines of jet-type engines. The inven tion is particularly useful in aerial missiles which require a compact power plant that develops large amounts of energy over a very short period of time. of the useof this invention are: the rocket-assisted takeoff or flight of aircraft; aerial missiles; boosters for surface vehicles. I

-The relative proportion of oxidizer-to-fuel used will depend upon the type of operation, the temperature of operation and the type of fuel and oxidizer being used. When using 90% H solution as the oxidizer and trimethyl thioborate as the fuel, between about 4 and 5 volumes of oxidizer are needed per volume of fuel.

Byway of example this invention is applied to the propulsion of a ground-to-air missile. The annexed figure which forms a part of this specification shows sche matically the bipropellant feed system and the motor of this missile. This same type of missile could be used as a ship-to-air missile. This missile is suitable for opera tions wherein the fuel and the oxidizer can be maintained at a temperature high enough to insure at least a short ignition delay, e.g., when using 90% H 0 as the oxidizer and trimethyl thioborate as the fuel, a temperature of about 0 F.

In the drawing vessel 11 contains a quantity of gas at high pressure; this gas must be inert with respect to the oxidizer and the fuel; suitable gases are nitrogen and helium. Herein helium is used as the inert gas. Helium from vessel 11 is passed through line 12 and through valve 13 which regulates the flow of gas to maintain a constant pressure beyond valve 13. From valve 13 helium is passed through lines 14 and 16 into vessel 17 and simultaneously through line 18 into vessel 19.

Vessel 17 contains the oxidizer. Helium pressure forces the oxidizer out of vessel 17 through line 21 to valve 22. Valve 22 is a solenoid actuated throttling valve. Suitable electrical lines connect valve 22 to an electrical source and operating switch (not shown) at the control chamber at the launching site. The oxidizer is passed through line 23 and injector 24 into combustion chamber 26. Combustion chamber 26 is provided with an outlet nozzle 27.

Vessel 19 contains the fuel. Vessels 17 and 19 are constructed to withstand the high pressure imposed by the helium gas. The gas pressure forces fuel from vessel 19 through line 28 to solenoid actuated throttling valve 29. Valve 29 is similar in construction and in actuation to valve 22. The fuel is passed through line 31 and in jector 32 into combustion chamber 26.

Valves 22 and 29 are of such a size and setting that a predetermined ratio of oxidizer-to-fuel is passed into combustion chamber 26. Injectors 24 and 32 are so arranged that the streams of oxidizer and fuel converge and contact each other forcibly, resulting in a very thorough intermingling of the fuel and the oxidizer.

The missileis launched by activating the solenoids on valves 22 and 29. In this example 4.5 volumes of 90% H 0 solution per volume of trimethyl thioborate is introduced into the combustion chamber. The oxidizer and the fuel react almost instantaneously upon contact in the combustion chamber; a large volume of very hot gas is produced in the combustion chamber, which gas escapes through orifice 27. The reaction from this expulsion of gas drives the missile toward its target.

Thus having described the invention, what is claimed is: r l

l. A method of generating gas, which method comprises injecting separately and essentially simultaneously into the combustion chamber of a gas generator (1) a hypergolic fuel consisting essentially of a thioborate having the empirical formula (RS) B wherein B represents Other examples the element boron, S represents the element sulfur and R represents a hydrocarbon radical selected from the class consisting of aliphatic and cycloaliphatic which contain not more than three carbon atoms and the total number of carbon atoms in the thioborate is between. 3 and 7 and (2) an oxidizer selected from the class consisting of (a) aqueous hydrogen peroxide solutions consisting of at least about weight percent of H 0 and the remainder essentially water and (b) aqueous hydrogen peroxideammonium nitrate solutions wherein the hydrogen peroxide-water portion consists of at least about 80 weight percent of H 0 and the remainder essentially water, in an amount and at a rate suificient to initiate a hypergolic reaction with and to support combustion of the fuel.

2. The method of claim 1 wherein said fuel is trimethylthioborate.

3. TheYmethod of claim 1 wherein said fuel is triethylthioborate.

4. The method of claim 1 wherein said oxidizer consists of about 80 weight percent of H 0 and the remainder essentially water.

5. The method of claim 1 wherein said oxidizer consists of about weight percent of H 0 and the remainder essentially water.

6. The method of claim 1 wherein said oxidizer consists of a solution of hydrogen peroxide, water and ammonium nitrate, wherein the nitrate content is about 30 weight percent and the hydrogen peroxide-water portion consists of about 80 weight percent of H 0 and the remainder essentially water.

7. The method of claim 1 wherein said oxidizer consists of a solution of hydrogen peroxide, water and ammonium nitrate, wherein the nitrate content is about 40 weight percent and the hydrogen peroxide-water portion consists of about 90 weight percent of H 0 and the remainder essentially water.

8. A method of initiating combustion in a reaction-type motor, which method comprises bringing together essen tially simultaneously in' said motor. a hypergolic fuel consisting essentially of trimethyl thioborate and aqueous hydrogen peroxide solution containing about 90 weight percent of hydrogen peroxide and the remainder essentially water in an amount and at a rate suflicient to initiate a hypergolic reaction with the fuel, and wherein said fuel and said solution are at a temperature above about 20 F.

9. A method of spontaneously generating gas, which method comprises contacting (l) a hypergolic fuel consisting essentially of trimethyl thioborate in an amount of at least about 40 volume percent and the remainder a liquid miscible hydrocarbon, and (2) an aqueous hydrogen peroxide solution containing about 90 weight percent of hydrogen peroxide and the remainder essentially water in an amount and at a rate suflicient to initiate a hypergolic reaction with and to support combustion of the fuel, and wherein said fuel and said peroxide are at a temperature of at least about +60 F.

10. The method of claim 9 wherein said hydrocarbon is a petroleum hydrocarbon fraction boiling between about 300 and 600 F.

11. The method of claim 9 wherein said hydrocarbon is an aromatic hydrocarbon boiling below about 600 F.

12. The method of claim 9 wherein said hydrocarbon is an olefinic hydrocarbon boiling below about 600 F.

References Cited in the file of this patent UNITED STATES PATENTS Leum Dec. 23, 1941 Rogers et a1 Oct. 17, 1950 OTHER REFERENCES 

1. A METHOD OF GENERATING GAS, WHICH METHOD COMPRISES INJECTING SEPARATELY AND ESSENTIALLY SIMULTANEOUSLY INTO THE COMBUSTION CHAMBER OF A GAS GENERATOR (1) A HYPERGOLIC FUEL CONSISTING ESSENTIALLY OF A THIOBORATE HAVING THE EMPIRICAL FORMULA (RS)3B WHEREIN B REPRESENTS THE ELEMENT BORON, S REPRESENTS THE ELEMENT SULFUR AND R REPRESENTS A HYDROCARBON RADICAL SELECTED FROM THE CLASS CONSISTING OF ALIPHATIC AND CYCLOALIPHATIC WHICH CONTAIN NOT MORE THAN THREE CARBON ATOMS AND THE TOTAL NUMBER OF CARBON ATOMS IN THE THIOBORATE IS BETWEEN 3 AND 7 AND (2) AN OXIDIZER SELECTED FROM THE CLASS CONSISTING OF (A) AQUEOUS HYDROGEN PEROXIDE SOLUTIONS CONSISTING OF AT LEAST ABOUT 80 WEIGHT PERCENT OF H2O2 AND THE REMAINDER ESSENTIALLY WATER AND (B) AQUEOUS HYDROGEN PEROXIDE-AMMONIUM NITRATE SOLUTIONS WHEREIN THE HYDROGEN PEROXIDE-WATER PORTION CONSISTS OF AT LEAST ABOUT 80 WEIGHT PERCENT OF H2O2 AND THE REMAINDER ESSENTIALLY WATER, IN AN AMOUNT AND AT A RATE SUFFICIENT TO INITIATE A HYPERGOLIC REACTION WITH AND TO SUPPORT COMBUSTION OF THE FUEL. 